The Commons on Flickr brings together images from some 25 institutions worldwide to exhibit "hidden treasures in the world's public photography archives". All of the images have no known copyright restrictions and are searchable within The Commons.
The 'Picture Australia: People, Places and Events’ group is an growing collection of images of social, political, contemporary and or historical events of national significance. It contains more than 1.6 million images from major collecting institutions. If you would like to, you too can contribute your Flickr images to this group.
This archive contains historical images from the US Library of Congress that have no known copyright restrictions.
Three other Flickr Search engines worth looking at are Compfight,Tag Galaxy, FlickrStorm To add attributions to your Flickr images at the same time as you get an embed code you might like to use ImageCodr
Three other Flickr Search engines worth looking at are
Compfight,Tag Galaxy, FlickrStorm
To add attributions to your Flickr images at the same time as you get an embed code you might like to use ImageCodr